Power pipe tongs



July 19, 1966 A. c. CATLAND 3,261,241

POWER PIPE TONGS Original Filed June 20, 1962 v '7 Sheets-Sheet 1INVENTOR ALFRED C. CATLAND BY WW ATTORNEY July 19, 1966 A. c. CATLANDPOWER PIPE TONGS 7 Sheets-Sheet 2 Original Filed June 20, 1962 INVENTORALFRED C. CATLAND WW ATTORNEY July 19, 1966 A. c. CATLAND 3,261,241

POWER PIPE TONGS Original Filed June 20, 1962 7 Sheets-Sheet 5 INVENTORALFRED C. CATLAND ATTORNEY July 19, 1966 c CATLAND 3,261,241

POWER PIPE TONGS Original Filed June 20, 1962 7 Sheets-Sheet 4 INVENTOR104 105 1038 60 ALF RED C. CATLAND BYWMV ATTORNEY July 19, 1966 A. c.CATLAND POWER PIPE TONGS 7 Sheets-Sheet 5 Original Filed June 20, 1962INVENTOR ALFRED C. CATLAND ATTORNEY July 19, 1966 A. c. CATLAND3,261,241

POWER PIPE TONGS Original Filed June 20, 1962 7 Sheets-Sheet 6 INVENTOR.ALFRED C. CATLAND ATTORNEY y 1966 A. c. CATLAND 3,261,241

POWER PIPE TONGS 7 Sheets-Sheet 7 Original Filed June 20, 1962 INVENTORALFRED C. CATLAND ATTORNEY United States Patent 3,261,241 POWER PIPETONGS Alfred C. Catland, Alhambra, Calif., assignor, by mesneassignments, to Byron Jackson, Inc., Long Beach, Calif., a corporationof Delaware Continuation of application Ser. No. 203,872, June 20, 1962.This application Feb. 17, 1965, Ser. No. 438,172 Claims. (CI. 81-57)This application is a continuation of US. application for LettersPatent, Serial No. 203,872, filed June 20, 1962, now abandoned, whichlatter application is a continuation-in-part of US. application forLetters Patent, Ser. No. 813,374, filed May 15, 1959, now abandoned.

The present invention relates to power tongs of the type employed inmaking up and breaking out pipe joints in strings of well pipe such aswell casing, drill pipe and tub- It is the practice in the drilling,completion and production of oil wells to employ tonging devicesengageable with the well pipe to impart rotation to a stand of such pipewhich is supported in the surface rigging above the Well so as to make athreaded connection of such stand of pipe with the pipe string extendinginto the well, or to remove such stand of pipe from the string of pipeleading into the well as the case may be. Hand tongs may be employed forthis purpose; however, power-operated devices have been developed, whichsubstantially expedite the procedure of rotating the stand of pipesupported in the well rigging, thus effecting a substantial savings intime in running into the well a string of pipe, or in removing suchstring of pipe from the well.

An object of the present invention is to provide a power tonging devicehaving a gripping mechanism automatically engagement with the pipe so asto effect rotation thereof, the tongs having a radial opening or throatpermitting application of the tongs to the pipe and removal of the tongsthere-from.

Another object of the invention is to provide a tonging head which isautomatically operable to engage the pipe to effect rotation thereof ineither direction upon reversal of the drive to the tonging head. Inaccordance with this objective, the tonging head is provided with aradial throat for the reception of the pipe to be rotated, and withinthe throat there is revolvably disposed a gripping mechanism comprisingan inner pipe engaging partial ring, this pipe engaging ring beingdriven by an outer drive ring and including a number ofcircumferentially spaced die means, certain of which are adapted to beautomatically moved into engagement with the pipe, or retracted fromengagement with the pipe responsive to relative rotation between theinner and outer rings. These die means are preferably arranged inangularly spaced relation about the pipe when engaged therewith, so asto impose uniform forces on the pipe, thus to minimize distortion orcrimping of the pipe.

A further object is to provide a throated tonging head includingrelatively fixed die means disposed in opposed relation to the throat incombination with die means movable into engagement with a pipe disposedin the head in such angularly spaced relation to the fixed die means asto impose on the pipe a force component urging the pipe into engagementwith the fixed die means, wherein the movable die means will be operatedresponsive to rotation of the tonging head in either direction. Withsuch a construction, the need for interchangeable fixed and shiftabledie means or roll-over tong hangers is avoided. Certain manufacturingeconomies also accrue by reason of a construction made in accordancewith this objective.

Other objectives and advantages of the invention will hereinafter bedescribed or will become apparent to those skilled in the art, and thenovel features of the invention will be defined in the appended claims.

Referring to the drawings:

FIG. 1 is a top plan view of a power tong made in accordance with theinvention, with a portion of the gear oase removed to expose the powertrain to the tonging head;

FIG. 2 is a side elevational view of the tong of FIG. 1;

FIG. 3 is an enlarged View in horizontal section as taken on the line3-3 of FIG. 2, but with certain of the parts shown in elevation;

FIG. 4 is an enlarged fragmentary view in section as taken on the line44 of FIG. 3;

FIG. 5 is an enlarged fragmentary view in section as taken on the line5-5 of FIG. 3;

FIG. 6 is an enlarged fragmentary view in section as taken on the line6-6 of FIG. 3;

FIG. 7 is a fragmentary view in section as taken on the line 7-7 of FIG.1;

FIG. 8 is an exploded detail view, more particularly illustrating thepartial pipe gripping and partial drive rings of the tonging head of thepresent invention; and

FIG. 9 is a view similar to FIG. 3, but illustrating a modified form ofthe invention; and

FIG. 10 is a view similar to FIG. 3 but illustrating a modified form ofthe invention.

Like reference characters in the several views of the drawings and inthe following detailed description designate corresponding parts.

Referring particularly to FIGS. 1 and 2, the tong of the presentinvention comprises three major components, namely, a tonging headgenerally designated 1 which is supported upon a lever generallydesignated 2, the lever 2 having disposed thereon a gear box generallydesignated 3.

The tonging head 1 comprises a frame or housing H composed ofcomplemental housing sections 4 and 5, secured together along themid-plane of the head as by a suitable number of through fasteners 6.The tonging head 1 has a pipe opening 7, and is also provided with aradial throat 8 leading into the pipe opening 7 along the longitudinalcenter of the tong.

Supported by the frame or housing H is a gate 9 piv-otally connected asat 10 to the frame or housing H at one side of the throat 8, and adaptedto bridge the throat and to be releasably latched at its free end to theframe or housing Hat the opposite side of the throat 8.

Referring to FIG. 3, latch means generally designated 11 are carried bythe gate 9. This latch means includes an arm 12 pivotally carried by thegate as at 13 internally thereof and projecting through the gate 9 toenable manual operation of the latch arm 12. Carried by the arm 12 is alatching lug 14, engageable in a recess 15 in frame or housing Hadjacent the mouth of the throat 8, and spring means 16 are employed tonormally bias the arm 12 in a position to effect engagement of the lug14 in the recess 15.

In addition, spring means 17 are pivotally supported as at 18 to theframe or housing H at the opposite side of the throat 8 from the recess15, and in spaced relation to the ivotal mounting 10 of the gate 9 tothe housing H. This spring means is adapted to bias the gate 9 to aclosed position and to bias the gate 9 to an open position respectively,as the line of force of the spring means passes over a center lineleading through the pivot support 10 of the gate 9 and the pivot support18 of the spring means 17.

The gate construction forms no part of the present invention andtherefore need not be described in further detail.

At its inner end the housing or frame H is secured to the lever 2 as bymeans of a suitable number of screw fasteners 19 extending throughvertical webs 20 of the lever 2 which are carried by transversely spacedside walls 21 of the lever.

The gear box 3 previously referred to is appropriately mounted at oneend to the frame or housing H, and at its other end is anchored to thefree end of the lever 2 as by anchor bolts 22. Disposed beneath the gearbox adjacent the free end of the lever, as shown in FIG. 2, is anappropriate motor device such as a hydraulic motor 23, which iscontrolled by an appropriate valve mechanism 24 disposed to one side ofthe gear box 3, and including an operating lever 25, so as to drive themotor output shaft in either direction.

It will be noted that the output shaft of the motor 23 is designated 26in FIG. 1, and has mounted thereon a drive gear 27, meshing with anidler gear 28 which is mounted on a shaft 29 journalled in the gear box3. The idler gear 28 is in turn engaged with a large gear 30 mounted ona shaft 31 which is also journalled in the gear box 3, and which has agear 32 mounted thereon and disposed beneath the large gear 30. Gear 32is in mesh with a gear 33 which drives shaft 34 on which it is mounted,the shaft 34 also having thereon beneath the gear 33, a gear 35. Gear35, as shown in FIG. 1, as well as in FIG. 3, is in mesh with a pair ofidler gears 36, 36 disposed at opposite sides of the longitudinal centerof the tong and mounted on shafts 37, 37 which are preferably journalledin the upper and lower section 4 and of the housing or frame H. Gears 36in turn are meshed with a pair of drive gears 38, 38 mounted on shafts39, these shafts also preferably being journalled in the housing orframe sections 4 and 5.

The gears 38 being driven by the gear train comprising gears 27, 28, 30,32, 33, 35 and36, constitute means for imparting rotation to an outerpartial drive ring generally designated 40, having on its outerperiphery a bull gear 41. The outer ring 49 has a side or radial openingtherein adapted, in a manner which will hereinafter be more particularlydescribed, to be aligned with the throat 8 through the frame or housingH for the reception of a pipe section.

As is best seen in FIGS. 4 and 5, the housing or frame H is generally ofchannel cross-section, and is formed with opposing arcuate upper andlower walls 42 and 43 respectively. Internally thereof the frame orhousing H is provided with a pair of circumferentially extended flanges44 and 45 in the housing sections 4 and 5, respectively, and disposed inopposed spaced relation to the upper and lower walls 42 and 43. At aplurality of circumferentially spaced points, rollers 46 mounted onshafts 47 are mounted within the housing or frame H, with the shafts 47supported in the opposing upper and lower walls 42 and 43 of the housingand the circumferentially extended flanges 44 and 45 (see FIG. 4).Accordingly, it will be noted that the rollers 46 constitute means forcontaining the outer partial ring 40 for rotation about its axis.

The outer partial ring 40 is vertically supported upon a wear ring orpartly circular bearing ring 48, which is secured to the lower wall 43of the housing H, as by means of a suitable plurality ofcircumferentially spaced fasteners 49. Also mounted on the outer surfaceof the lower wall 43 of the housing H is an L-shaped partly circularring 50, constituting a shield for brake means which will hereinafter bemore particularly described. In addition, there. is a wear ring orpartly circular bearing ring 51 carried at the inner periphery of theupper wall 42 of the housing and engaged with the outer partial ring 40,so as to constrain the partial ring 40 against substantial axial playwithin the housing or frame H. This bearing ring 51 is secured to thetop wall 42 of housing H as by means of a suitable number of fasteners52 disposed in circumferentially spaced relation.

The outer partial ring 40 is preferably a casting which as shown inFIGS. 4, 5 and 8, is of channel section ad- Ad jacent the extremitiesthereof, there being an arcuate wall designated 53 at the innerperiphery of the outer ring 40 and at the rear of the ring in opposedrelation to the lateral pipe-receiving opening in the ring, so as toprovide a rigid cross-sectional box configuration.

Disposed within the outer partial ring 40 is an inner partial ringgenerally designated 60, which also is preferably a casting having alateral pipe opening adapted, in a manner which will hereinafter moreparticularly appear, to be aligned with the pipe opening in the outerring 40.

The inner ring 60 as shown herein, comprises an upper wall 61 and alower wall 62, having at its base, in opposed relation to the pipeopening therein, an inner vertical wall 63 and an outer vertical wall64. Accordingly, at its base, the inner ring 60 is substantially ofbox-like cross-section, while adjacent to the extremities of the ring 60there is a radial space for the reception of a pair of jaws generallydesignated 65.

The jaws 65 respectively comprise a body 66 having at one end a pair ofmounting lugs 67, 67 (see FIG. 6) through which extends a pin 68 aboutwhich the jaws 65 are adapted to pivot for swinging movements towardsand away from a section of pipe disposed within the pipe opening in theinner ring 60. Preferably the pin 68 is threaded as at 68 so as to beretained in the upper wall 61 of the inner ring 60, and extends throughthe mounting lugs 67 of the respective jaws 65, and into the lower wall62 of the inner ring 60.

In order to bias the jaws outwardly with respect to the pipe opening inthe inner ring, a torsion spring 69 is preferably disposed on acentering sleeve 7'0 disposed about the respective pins 68, thesesprings 69 having their ends 69a engaged as best seen in FIG. 3, withthe inner vertical wall of the inner ring 60 and with the jaws betweenthe mounting lugs 67, in such a manner that inward movement of the jaws65 about the pivot pins 68 will store energy in the springs 69 to biasthe jaws 65 outwardly.

Each of the jaws 65 is preferably provided with a removable pipegripping die segment 71 retained as by pins 72 (see FIG. 8) in undercutor dove-tailed vertically extended slots 73 in the pipe engaging end 74of the respective jaws 65.

In addition, the inner ring 60 is provided with relatively stationarydie means disposed in opposed relation to the pipe opening in the innerring 60, and in the illustrative embodiment such die means comprises adie carrier block 75 disposed in a vertically extended slot 76 in thewall 63 of the inner ring 60, and having at its upper and lowerextremities outstanding cars 77 for the reception of through bolts 78,whereby the block 75 is removably secured to the inner ring 60.Removably carried by the die block 75 is a die insert 79 disposed in anundercut vertically extended slot 80 in the block, and contained thereinas by pins 81 or the like.

In order to effect movement of the jaws 65 about the pivot pins 68, thejaws 65 and the outer ring 40 have cooperative cam means to force thejaws inwardly responsive to slight relative angular displacement of theouter ring 40 with respect to the inner ring 60. In the illustrativeembodiment of FIGS. 1 through 8, such cam means comprises a pair ofcompound cams 85, 85 carried by the outer ring 40, or integrally formedin the outer ring as may be desired. These compound cams 85 are eachherein shown as being removably secured within the outer ring 40 as by apair of fasteners 86.

As best seen in FIG. 3 the pair of cams 85 provide a pair of opposedramps 85a, 85a, and a pair of opposed ramps 85b, 85b engageable withrollers 87 rotatably supported by a shaft 88 journalled in opposed cars89, 89 projecting outwardly from the pipe engaging end '74 of therespective jaws 65. Accordingly, upon relative angular movement betweenthe outer ring 40 and the inner ring 60 in one direction, the opposedramps 85a, 85a will engage the rollers 87 of the jaws 65 to cam the jawsinwardly about the pivot pin 68. On the other hand, relative angulardisplacement between the outer ring 40 and the inner ring 60 in theother direction will bring the opposed ramps 85b, 85b into engagementwith the rollers 87 to effect inward pivotal movement of the jaws 65about the pins 68.

Intermediate the ramps 85a and 85b of the respective compound cams 85,is an arcuate neutral section 850 constituting the low point of thecompound cams, whereby the jaws will be caused by springs 69 to swingoutwardly away from a section of pipe disposed in the pipe openings asthe rollers 87 ride down either ramps 85a or ramps 85b onto neutralsection 850.

From the foregoing, it will be apparent that the inner ring assemblyconstitutes a pipe gripping mechanism operable responsive to rotation ofthe outer ring 40 relative to the inner ring 60. In order to effect suchrelative rotation, brake means as previously generally referred to areemployed to frictionally resist rotation of the inner ring 60 relativeto the housing or frame H. Such brake means in the illustrativeembodiment, as best seen in FIGS. 4, 5 and 6, comprises a brake band 90,having a friction lining material 91 thereon engageable with a dependingflange 92 on the lower wall 62 of the inner ring 60. The brake band 90is connected to the housing or frame H in any suitable manner, as bypins or the like, as more particularly shown and described in US. PatentNo. 2,650,070 issued August 25, 1953 to C. A. Lundeen.

While it will be apparent that if desired the inner ring 60 and theouter ring 40 may be positioned relative to the throat 8 through thehousing or frame H, so as to permit the application of the tong to, andthe removal of the tong from a pipe joint, by means of manipulation ofthe control valve 25 which controls the drive to the outer ring throughthe gears previously described, it is preferred that means he providedfor relatively positioning the inner ring and the outer ring, and thatmeans also be provided for relatively positioning the outer ring and thehousing or frame.

Accordingly, an inner ring positioning device generally designed 100 andbest illustrated in FIGS. 1 and 7 is employed to alternately limitrelative rotation between the inner and outer ring 60 and 40respectively in one direction, so that the radial pipe openings thereinare in radial alignment.

The positioning device 100 includes a body 101 mounted on the uppersurface of the outer ring 40, as by a suitable number of fasteners 102,and overlying the inner ring 60. In the upper wall 61 of the inner ringis a pair of circumferentially spaced and arcuate slots 103 and 104,there being an abutment section 105 between the slots 103 and 104.Shiftably disposed in the body 101 is a pair of pins 103a and 104a,having inner ends 103b and 10412 which are alternately engageable in thecircumferentially extended slots 103 and 104. Each of these inner ends1031) and 10% is provided with a bevelled surface 1030 and 104C,respectively, alternately engageable with a detent 106 which isshiftably disposed in the body 101 for movement into engagement with therespective bevelled surfaces 103a and 104c upon depression of the pins103a and 104a.

Each of the pins is provided with a head 103d and 104d, with which isengaged a compression spring 1031: and 104e; these springs are seated inbores 10111 in the body 101 so as to normally bias the respective pinsoutwardly with respect to the slots 103 and 104. However, it will beobserved that when one pin is manually depressed, the spring acting onthe other pin will shift the latter outwardly; thus camming the detent106 into engagement with the bevelled surface of the other pin so thatdepression of one pin automatically effects release and retraction ofthe other pin from slot103 or 104, as the case may be, by means of thespring engageable with the respective pin head, and retention of the pinwhich is manually depressed in the respective slots 103 or 104, as thecase may be, will also be effected. However it will be noted that witheither of the pins 103a and 104a disposed in the slots 103 or 104 andengaged with the abutment 105, the outer ring 40 and the inner ring 60will be relatively angularly positioned such that the lateral pipeopenings therethrough are in alignment.

In order to position the outer ring 40 relative to the housing or frameH, positioner valve means 107 (see FIG. 1) are employed, such valvemeans being more particularly shown and described in US. Patent No.2,780,950, dated February 12, 1957, to J. H. Province. The positionervalve means 107 as will be apparent upon reference to the just-mentionedPatent No. 2,780,950, is adapted to cooperate with a positioner cam 108,which, as best seen in FIG. 8 is disposed on the upper surface of theouter ring 40 so as to actuate the valve 107. Connecting the positionervalve 107 to the control valve mechanism previously described arehydraulic lines 109, 109 as best seen in FIGS. 1 and 2.

It will be apparent that the function of the positioner valve means 107is to shut off the flow of power fluid to the motor 23 when the controlvalve 25 is conditioned to render the positioner valve 107 operative,whereby the outer ring 40 will cease rotation when the pipe openingtherethrough is aligned with the throat of the housing or frame H.

The operation of the present tong as specifically described in theforegoing is as follows, assuming the tong to be operating in a mannersuch as to effect clockwise rotation of the outer ring 40 andconsequently the pipe gripping means as shown in FIGS. 1 and 3.

It will be noted with reference to FIG. 7, that end 103b of inner ringpositioning pin 103a is depressed in slot 103 so as to engage stopprojection 105. Accordingly, the outer ring 40 which carries the body101 is free to rotate in the clockwise direction relative to the innerring 60. However inner ring 60 is frictionally restrained against suchrotation by reason of frictional engagement of the friction liningmaterial 91 on the brake band 90 with the depending flange 92 which iseffectively an integral part of the inner ring 60. Such rotation of theouter ring 40 relative to the inner ring 60, therefore, will causeengagement of opposing cam surfaces b of camming means 85 with therespective rollers 87 of jaws 65, so that the jaws will be pivoted aboutpins 68 into engagement with a tool joint or section of well casing C orother pipe disposed within the pipe opening in the inner ring 60. Suchpivotal movement of the jaws 65 will force the pipe or casing C intoengagement with the die means comprising die 79 which is at a locationopposite the pipe opening in the outer partial ring 40.

In this connection it will be noted that the die 79 constitutes ineffect die means which are virtually carried by the outer partial ring40, inasmuch as the inner jaw-carrying ring 60 is mounted for rotationin the outer ring 40.

Further, it should be noted that the dies 71 carried by thepipe-engaging ends 74 of jaw-s 65 are spaced about the pipe openingrelative to the die 79 at the base of the inner ring 60, such that therespective dies will have contact with the pipe at circumferentiallyspaced points about the latter.

It will be recognized that in order toprovide a component of force byreason of engagement of the dies 71 with the casing or pipe C, tendingto urge the casing or pipe C into engagement with the die 79, that thedies 71 must engage the pipe at points spaced from the die 79 at leastslightly in excess of degrees. Stated otherwise, it might be said thatthe present invention provides shiftable die means, namely, dies 71carried by jaws 65 engageable with sectors of a well pipe disposedWithin the pipe gripping mechanism which are at the opposite side of adiametrical line extending across the pipe from the die means includingthe die 79, which, if desired, may have engagement with the pipe over asubstantial angular extent in opposed relation to the dies 71. Symmetryof the pipe engaging die system, however is preferably maintained inorder to equally distribute the pipe-engaging forces about the pipe.

As the jaws 65, as previously mentioned, are caused to swing intoengagement with the well pipe or casing C, so that the latter is grippedbetween dies 71 and 79, the inner ring 60 by reason of engagement ofrollers 87 with cam surfaces 85b will be locked up with the outer ring40, so that rotation of the outer ring 40, the inner ring 60 and thepipe or casing C, as a unit, will result. When it is desired to releasethe casing or pipe from the grip- .ping mechanism, control valve means25 will be actuated to reverse the direction of rotation of the outerring 40, whereupon the rollers 87 will ride down the opposite ramps 85bto the circumferentially extended low section 850 of the respectivecompound cams 85. At this time stop pin end 103b which is disposed inslot 103 as shown in FIG. 7, will abut with the stop projection 105 soas to prevent further counterclockwise rotation of the outer ring 40relative to the inner ring 60, so that these rings will accordinglyrotate in a counterclockwise direction in unison.

Such unitary counterclockwise rotation will continue until such time asthe positioning cam 108 cooperates with positioning valve means 107previously referred to, to halt rotation of the outer ring 40, at whichtime the radial pipe openings in the outer ring 40 and the inner ring 60will be aligned with the throat 8 through the housing or frame H. Thus,removal of the tong from the well pipe or casing C is permitted uponopening of the gate 9, and in addition the tong gripping mechanism is inposition for reapplication of the tong mechanism to another pipe jointto be made up.

In the case where pipe joints are to be broken out by means of thepresent tong, it will now be recognized that it is only necessary todepress positioning pin 104a so that end 104b projects into slot 104 ininner ring 60, and pin 103a is retracted, whereupon relative rotationbetween the outer ring 40 and the inner ring 60 will be permitted onlyin a direction in which the outer ring rotates in a counterclockwisedirection as viewed in FIGS. 1 and 3, so as to effect engagement ofopposing cam surfaces 85a, 85a, with rollers 87.

Referring now to FIG. 9 wherein a modified construction is shown, itwill be noted that the same reference characters are employed as thoseemployed in FIGS. 1 through 8, except in respect to the camming meansfor effecting movement of the pipe-engaging jaws towards the well pipeor casing C.

In FIG. 9 it will be noted that the outer ring 40 carries rollers 287mounted upon shafts 234. In addition, the jaws 265 are provided with acompound camming surface including oppositely disposed cam surfaces 285aand 285b, with an intervening neutral section 2850 on the respectivejaws 265, so that the same jaw-actuating effect as that obtained by theconstruction of FIG. 3 is also attained by the construction of FIG. 9.Otherwise, the construction of FIG. 9 is idential to FIG. 3 and need notbe further described.

It will be appreciated that in the respective embodiments of the pipegripping mechanisms hereinabove specifically described, the provision ofthe camming surfaces 85a, 85b, 85c, on the outer partial ring 40, asbest seen in FIG. 3, for engagement with a cam follower roller 87carried by the respective jaws 65, on the one hand, and as in FIG. 9 theprovision of camming surfaces 285a, 285b, 285c on the respective jaws265 engaged by the rollers 287, are principally matters of choice. Ineither case the camming effect is caused by the angular movement of theouter ring 40 relative to the die carrying inner ring 60, so that in therespective structures of FIG. 3 and FIG. 9 the surfaces 85a and 85bconstitute a driving cam surface, while the jaws 65 and particularly theroller thereon constitute a follower; while in the structures shown inFIG. 9 the rollers 287 constitute driving cam elements engaged with theopposing surfaces of jaws 265 which constitute followers.

Moreover, it will be noted upon reference to FIGS. 3 and 9 particularly,that the die insert 79 in each view is provided with a series ofvertically extended teeth, each of which constitutes die means.Therefore, the die insert 79 provides die means disposed in the adjacentquadrants of a circle formed on the opposite sides of the center line ofthe pipe opening 8 through which the casing passes into the grippingmechanism. In addition the dies 71, when the jaws 65 and 265 areactuated inwardly, engage the casing the casing C in the two quadrantsof a circle in opposed relation to the die means constituted by the rowsof teeth on the die insert 79, and in the two quadrants of a circle onthe opposite side of a line perpendicular to the center line of saidopening 8, intersecting with said center line at the axis of thegripping mechanism.

Referring now to FIGURE 10 wherein another modified construction isshown, it will be noted that the same reference characters are employedas those employed in FIGS. 1 through 9 except as to those parts specificto the jaw system shown.

In FIG. 10 it will be noted that the outer ring 40 carries rollers 287mounted upon shafts 234 in a manner like the rollers are carried andmounted as shown in FIG. 9. Likewise, the jaws 365 are provided with acompound camming surface including oppositely disposed cam surfaces 385aand a neutral section 3850 on the respective jaws 365, so that the samejaw-actuating effect as that obtained by the tong construction of FIGS.3 and 9 is also obtained by the construction of FIG. 10 except for thefact that in this construction the camming effect, due to the rollers287 and the camming surfaces 285a and 2850 to move the jaws 365 to pipeengaging position, caused by the angular movement of the outer ring 40relative to the inner ring 60, will always be clockwise, and angularmovement of the outer ring relative to the inner ring to move the jaws365 to a retracted position will always be counterclockwise as shown inthe drawing.

It is to be noted that the jaws 365 and their respective cammingsurfaces and rollers are arranged to accommodate a small pipe C such asshown in FIG. 10. The die insert 79 is provided with a die carrier block75 which is thicker than the preceding figures so as to place the dieinsert 79 closer to the center of the pipe C to properly cooperate withjaws 365. The use of a small pipe C in this figure is for purposes ofillustration of the versatility of the tong herein disclosed.

Jaws 365 in FIG. 10 are pivoted about pins 368 on the carrier so as tomove inwardly and outwardly thereabout in a manner similar to the jaw ofFIGS. 1-9. However, in this fiure the left jaw 365 is provided with atorsion spring 369 disposed about pin 368 and which has its ends 369aengaged with a vertical inner wall 363 of the inner ring 60 and with thejaw 365 in such a manner that inward movement of the jaw 365 about thepivot pin 368 toward pipe gripping position will store energy in thespring to bias this jaw 365 outwardly or toward retracted position.Thus, spring 369 urges the left jaw towards retracted position and holdsit in retracted position when the inner ring and outer ring are in sideopening aligned position.

It will be noted that the other jaw 365 (i.e., to the right of thepreviously described jaw) is not provided with a spring but is providedwith an ear or lug 390 extending in outward direction so as to beoperatively interposed between the roller 287 and a roller 287a mountedon the inner ring. Lug or ear 390 is provided with a camming and holdingsurface 392 which functions in response to the rotation of the outerring 40 to move this jaw 365 from a pipe gripping position to aretracted position and holds the inner and outer ring in a position sothat the inner and outer ring will rotate together upon further rotationof the rings. The spacing between roller 287 and 287a is such that thelug 399 is always interposed therebetween.

From the above, it can be seen that this jaw construction operates in ageneral way like the jaw mechanisms of the preceding FIGS. 1-9 exceptthat in the preceding jaw mechanism a double spring system was used,that is, a biasing spring 69 was utilized to retract and hold each jawretracted whereas in the instant case, one of the jaws is provided witha lug or ear which serves to retract and hold this one jaw in retractedposition and to hold the inner ring and outer ring together uponcontinued rotation of these rings after the jaws have been retracted.This jaw system further incorporates other features of the tongs of thepreceding figures including such items as the stop mechanism of FIG. 7.

While the specific details of the invention have been herein shown anddescribed, changes and alterations may be resorted to without departingfrom the spirit thereof as defined in the appended claims.

I claim:

1. A power tong for rotating a pipe comprising:

a frame having a central pipe opening and a throat leading to saidcentral pipe opening,

a pair of relatively rotatable rings comprising an outer ring and aninner ring disposed in said pipe opening, each of said rotatable ringshaving side pipe openings so that a pipe may enter said side pipeopening and said throat to said central pipe opening,

power transmission means for rotatably driving said outer ring in eitherdirection,

pipe gripping means on said inner ring including a plurality of radiallymovable, angularly spaced die means, jaw means pivotally supporting eachof said radially movable die means for swinging movements toward andaway from said central pipe opening, and cooperative camming means onsaid jaw means and on said outer ring for carnming said jaw means towardsaid central pipe opening upon rotation of said outer ring in eitherdirection from an intermediate position with respect to said inner ring,

means for moving said jaw means away from said cent-ral pipe openingwhen said outer ring is moved towards said intermediate position withrespect to said inner ring, and

inner ring positioning means mounted on said outer ring and engageablewith said inner ring for limiting relative rotative movement of saidrings when said outer ring is rotated to said intermediate position withrespect to said inner ring to position said rings so that said sideopenings are aligned to allow a pipe to be moved laterally through saidside openings.

2. The power tong claimed in claim 1, wherein said inner ringpositioning means includes stop means on said inner ring and meansmounted on said outer ring for engaging said stop means on either sideof said stop means depending upon the direction of rotation of saidouter ring.

3. The power tong claimed in claim 2, wherein the stop means is definedby a pair of circumferentially spaced,

arcuate slots in said inner ring and wherein said means for engagingsaid stop means comprises a body member having a pair of pin means whichare alternatively positioned in either of said slots, and resilientmeans and detent means operatively connected with said pin means so thatdepression of one pin into one of said slots effects the release andretraction of the other of said pin means from engagement with the otherslot for reversal of opera- :tion of said inner ring positioning device.

4. Power tongs, comprising:

a frame,

a ring rotatably mounted on the frame,

a carrier having a central opening therein and supported =for rotationeoaxially of the ring, the ring and carrier having side openings thereinalignable in one relative rotative position therebetween to pass a pipeinto and out of the central opening of the carrier,

means for rotating the ring with respect to the carrier,

a jaw fixed to the carrier opposite the side opening therein,

a pair of jaws mounted on the carrier for movement between a retractedposition for passing a pipe and an operative position for gripping apipe on opposite sides of the fixed jaw,

means responsive to rotation of the ring with respect to the carrier inone direction from side opening aligning to another position,respectively, to move the jaws from retracted to operative positions,and responsive to rotation of said ring with respect to the carrier inthe opposite direction from said other to side opening aligning positionto move the jaws from operative to retracted position and hold them insaid retracted position, and

carrier positioning means mounted on said ring and cooperating with saidcarrier to align said side openings upon retraction of said jaws fromoperative to retracted position by rotation of said ring in saidopposite direction and to rotate the carrier with the ring upon hurt-herrotation of said ring in said opposite direction.

5. The power tongs claimed in claim 4, wherein said carrier positioningmeans includes a pair of sh-iftable pins tor engaging abutment means onsaid carrier when said side openings are aligned and means forpermitting said pins to be shifted selectively and alternatively toengage said abutment means depending upon the rotation of said ring.

References Cited by the Examiner UNITED STATES PATENTS 2,618,468 11/1952Lundeen 81-57 2,703,221 3/ 1955 Gardner 8157 2,879,680 3/ 1959 Beeman etal 8153 2,989,880 6/1961 Hesser et al. 8153 3,180,186 4/1965 Catland8157 WILLIAM FELDMAN, Primary Examiner.

JAMES L. JONES, JR., Examiner.

1. A POWER TONG FOR ROTATING A PIPE COMPRISING: A FRAME HAVING A CENTRALPIPE OPENING AND A THROAT LEADING TO SAID CENTRAL PIPE OPENING, A PAIROF RELATIVELY ROTATABLE RINGS COMPRISING AN OUTER RING AND AN INNER RINGDISPOSED IN SAID OPENING, EACH OF SAID ROTATABLE RINGS HAVING SIDE PIPEOPENINGS SO THAT A PIPE MAY ENTER SAID SIDE PIPE OPENING AND SAID THROATTO SAID CENTRAL PIPE OPENING, POWER TRANSMISSION MEANS FOR ROTATABLYDRIVING SAID OUTER RING IN EITHER DIRECTION, PIPE GRIPPING MEANS ON SAIDINNER RING INCLUDING A PLURALITY OF RADIALLY MOVABLE, ANGULARLY SPACEDDIE MEANS, JAW MEANS PIVOTALLY SUPPORTING EACH OF SAID RADIALLY MOVABLEDIE MEANS FOR SWINGING MOVEMENTS TOWARD AND AWAY FROM SAID CENTRAL PIPEOPENING, AND COOPERATIVE CAMMING MEANS ON SAID JAW MEANS AND ON SAIDOUTER RING FOR CAMMING SAID JAW MEANS TOWARD CENTRAL PIPE OPENING UPONROTATION OF SAID OUTER RING EITHER DIRECTION FROM AN INTERMIDATEPOSITION WITH RESPECT TO SAID INNER RING, MEANS FOR MOVING SAID JAWMEANS AWAY FROM SAID CENTRAL PIPE OPENING WHEN SAID OUTER RING IS MOVEDTOWARDS SAID INTERMEDIATE POSITION WITH RESPECT TO SAID INNER RING, ANDINNER RING POSITIONING MEANS MOUONTED ON SAID OUTER RING AND ENGAGEABLEWITH SAID INNER RING FOR LIMITING RELATIVE ROTATIVE MOVEMENT OF SAIDRINGS WHEN SAID OUTER RING IS ROTATED TO SAID INTERMEDIATE POSITION WITHRESPECT TO SAID INNER RING TO POSITION SAID RINGS SO THAT SAID SIDEOPENINGS ARE ALIGNED TO ALLOW A PIPE TO BE MOVED LATERALLY THROUGH SAIDOPENINGS.